<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>椭圆</title>
</head>
<body>
<canvas id="myCanvas" width="600" height="500" style="border: 1px solid;"></canvas>

</body>
<script type="text/javascript">

    var c=document.getElementById("myCanvas");
    var cxt=c.getContext("2d");
    cxt.fillStyle="#FF0000";
    cxt.beginPath();
    cxt.arc(70,18,15,0,Math.PI*2,true);
    cxt.closePath();
   // cxt.fill();
    cxt.stroke();
</script>

</html>